Pancreatic cancer is a common malignant tumor of the digestive system. Because of the atypical symptoms in the early stage, when diagnosed, most of them are already in the advanced stage of the disease and lose the chance of surgery, and many patients have to suffer from severe pain as a result. Radiation therapy is still one of the main methods of pancreatic cancer treatment. In the past, external irradiation was mainly used. External irradiation is the application of external radiation source to reach the tumor through the normal tissues of human body, because the pancreas is located in the deep posterior peritoneum of the upper abdomen and there are tissues such as stomach, colon, bile duct and liver in front of it, and these tissues are more sensitive to radiation and less tolerable, and the irradiation treatment of pancreatic cancer requires avoiding these organs as much as possible, so as to reduce nausea, vomiting or abnormal liver function caused during radiotherapy. This can reduce the adverse effects such as nausea, vomiting or abnormal liver function during radiotherapy. Even so, it is very likely to cause bleeding, perforation or stricture of the stomach and intestines. In order to achieve the radiation dose for tumor treatment, radioactive particles are placed directly into the tumor, and the tumor receives high dose radiation therapy locally through the low-energy γ-rays emitted by the local radiation source, which not only can achieve more ideal treatment effect, but also reduce the radiation damage to the surrounding normal tissues.